package com.wyh.springcloud.order.lb.impl;


import com.wyh.springcloud.order.lb.LoadBalancer;
import lombok.extern.slf4j.Slf4j;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.stereotype.Component;

import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * @author wyh
 * @version 1.0
 * @date 2021/11/16 17:10
 */
@Component
@Slf4j
public class MyLoadBalancerImpl implements LoadBalancer {

    private AtomicInteger atomicInteger = new AtomicInteger(0);

    public final int getAndIncrement(){
        int current;
        int next;
        do {
            current = this.atomicInteger.get();
            next = current >=2147483547 ? 0 : current+1;
        }while (!this.atomicInteger.compareAndSet(current,next));
        log.debug("*****next:{}",next);
        return next;
    }

    @Override
    public ServiceInstance instances(List<ServiceInstance> serviceInstances) {

        int index = getAndIncrement() % serviceInstances.size();

        return serviceInstances.get(index);
    }
}
